DESCRIPTION: Hereditary Benign Intraepithelial Dyskeratosis (HBID) is an autosomal dominant, cell proliferation disorder characterized by intraepithelial dyskeratosis of the conjunctiva of the eye and oral mucosa, producing opaque epithelial plaques. HBID is found primarily in members of the Native American Haliwa-Saponi Indian Tribe and their relatives, which include individuals of African American and Caucasian descent. This disorder, which can lead to blindness, also has reported seasonal variations, suggesting environmental interactions as well. The PI has identified 2 branches of a large (over 350 individuals), inbred Haliwa-Saponi family with HBID, representing a single founding mutation. Identification of the HBID gene defect will allow initiation of studies into effective treatment of this disorder and provide information into the normal mechanisms of cell proliferation. The investigator has already collected 46 individuals (24 affected) from this large family and had excluded the 2 keratin clusters as candidate genes, that are defected in a similar disorder (White Spong Nevus). The principal investigator proposes to identify, examine and collect additional members of this family for pedigree linkage analysis to establish its chromosomal localization. Clinical characterization of the disorder, its extent and seasonal variation will be examined. Cell lines of conjunctival epithelium from affecteds will be established and evaluated. Once linkage is established, fine mapping of the gene will be performed using the combinations and haplotype analysis. Physical contigs of YAC'S and PAC'S will be formed across the minimal candidate region and used to identify candidate genes. These will be evaluated and the gene for HBID will be identified and the protein characterized.